One of the terms we hear frequently these days, out there in the gastropub wild, is “house-made.” House-made pickles are almost sparkly with holiday spice. House-made ketchup is spiked with curry powder. We hear it so frequently in the days following the Great Gastropub Revolution of the 2000s that it’s easy to take it for granted.

Over at Deep Ellum’s brand-spanking new Filament (from Matt McCallister), where chef Cody Sharp has unleashed the kraken of super secret burger, “house-made” isn’t taken lightly. Creamy and beautifully salty and messy, Filament’s top-secret burger, which unveils itself only at night when the burger signal goes shooting into the sky, is a labor of love.

The bun is homemade, a potato and whey mixture that gives off a sturdy chewiness alongside a lightly buttered crunch. Benne seeds, essentially heirloom sesame seeds, are showered on top of the glistening bun. This isn’t a bun that blows apart when you handle it. The burger is also house-ground, a blend of 50 percent brisket and 50 percent “finger meat,” which sounds like a part of the animal George Romero came up with. Pickles are house-made too, a briny, forest-green bunch.

It's late on a weekday and I'm at the Filament bar, about to tackle what looks to be a “treat yo’self” burger, and chatting with Sharp. He’s proud of the burger. He tells me they also made their own salt concoction, to make the patty pop (any burger lover will tell you a good burger takes a hefty coat of salt), which he lovingly refers to as “gangster salt.” He was hush-hush on the contents of gangster salt.

He leaves me with the new burger, and I can sense people’s eyes are headed my direction. There’s a burger?! It’s off-menu for now. Keep it secret; keep it safe. Here are the details, via chef Cody: Filament will sell 20 a night, seven nights a week, starting at 9 p.m. When they run out, they run out. “It’s truly a house-made burger,” he says. A first bite reveals why its distribution is being monitored so closely.

All of those house-made ingredients come together with the rest — a buttery disc of charred white onion, decadent mayo and a winter blanket of American cheese — for some real, indulgent burger madness. Messy and medium rare and cheesy. The whole thing felt so ceremonial that I was tempted to thank the burger for its time. Thank you for meeting me here, burger. Don’t ignore the bun, either — its texture is unlike any in North Texas.

Also, it comes with crinkle-cut fries! Those puppies are tossed in a bath of wonderful animal fats, according to the chef, and they’re deeply crunchy. Sharp also talked about one of his favorite burgers in the area: Adair’s. Like Deep Ellum itself and Adair’s burger, Filament’s version isn’t pretentiously tweezered — it’s a fun, exuberant mess of a burger. The house made it, and you know that when you see it.

You won’t take it for granted. Filament, 2626 Main St., 214-760-1080, filamentdallas.com.